Similarity of salivary microbiome in parents and adult children.

BACKGROUND: Human saliva contains approximately 700 bacterial species. It has been reported that the salivary microbiome of a large family of closely related individuals consisting of multiple households is similar but the relatedness of salivary bacteria between generations of parents and their children has not yet been investigated. The objectives were to investigate the entirety of salivary bacterial DNA profiles and whether and how families share these profiles and also compare these communities between grandparents and their first daughter generations (F1) using 16S rRNA gene amplicon sequencing. RESULTS: The most abundant phyla in two separate families were Firmicutes, Bacteroidetes, Proteobacteria, Fusobacteria and Actinobacteria. Family ties explained 13% of the variance between individuals' bacterial communities (R 2 = 0.13; P = 0.001). Mothers shared more OTUs with adult children compared to fathers, but this linkage seemed to be weaker in the nuclear family with older adult children. We identified 29 differentially abundant genus level OTUs (FDR < 0.05) between families, which accounted for 31% of the total identified genus level OTUs. CONCLUSIONS: Our results indicate that adult family members share bacterial communities and adult children were more similar to mothers than fathers. The observed similarity in oral microbiome between parent-child pairs seemed to weaken over time. We suggest that our analysis approach is suitable for relatedness study of multigenerational salivary bacteria microbiome.

Increased tooth brushing frequency is associated with reduced gingival pocket bacterial diversity in patients with intracranial aneurysms.

OBJECTIVES: The objective of this study was to investigate the association of tooth brushing frequency and bacterial communities of gingival crevicular fluid in patients subjected to preoperative dental examination prior to operative treatment for unruptured intracranial aneurysms. METHODS: Gingival crevicular fluid samples were taken from their deepest gingival pocket from a series of hospitalized neurosurgical patients undergoing preoperative dental screening (n = 60). The patients were asked whether they brushed their teeth two times a day, once a day, or less than every day. Total bacterial DNA was isolated and the V3-V4 region of the 16S rRNA gene was amplificated. Sequencing was performed with Illumina's 16S metagenomic sequencing library preparation protocol and data were analyzed with QIIME (1.9.1) and R statistical software (3.3.2). RESULTS: Bacterial diversity (Chao1 index) in the crevicular fluid reduced along with reported tooth brushing frequency (p = 0.0002; R2 = 34%; p (adjusted with age and sex) = 0.09; R2 = 11%) showing that patients who reported brushing their teeth twice a day had the lowest bacterial diversity. According to the differential abundant analysis between the tooth brushing groups, tooth brushing associated with two phyla of fusobacteria [p = 0.0001; p = 0.0007], and one bacteroidetes (p = 0.004) by reducing their amounts. CONCLUSIONS: Tooth brushing may reduce the gingival bacterial diversity and the abundance of periodontal bacteria maintaining oral health and preventing periodontitis, and thus it is highly recommended for neurosurgical patients.

The dental infections in patients undergoing preoperative dental examination before surgical treatment of saccular intracranial aneurysm.

OBJECTIVE: Dental bacterial DNA and bacterial-driven inflammation markers have previously been detected in intracranial aneurysm tissue samples. This study aimed (i) to assess the possible presence of dental infectious foci, (ii) and the possible association between typical odontogenic bacteria and clinical dental findings in patients undergoing pre-operative dental examination before surgical treatment of saccular intracranial aneurysm. Ninety patients with an intracranial aneurysm were recruited to the study, and the patients' teeth were routinely investigated. Clinical data and bacterial samples from the gingival pockets were collected from a subpopulation of 60 patients. Five typical dental pathogens and total bacteria amounts were measured from gingival samples using real-time quantitative PCR. RESULTS: The amounts of total bacterial and Fusobacterium nucleatum DNA were significantly higher in the patients with ≥ 6 mm gingival pockets than patients without them (p < 0.01 and p < 0.01, respectively). A total of 43% of patients with an aneurysm had gingival pockets of 6 mm or deeper. Dental infectious foci are fairly common in the Finnish population, with the prevalence of severe periodontitis being around 20%. The frequency of chronic dental infections, especially periodontitis seems to be higher in patients with intracranial aneurysm.

Bacterial DNA findings in ruptured and unruptured intracranial aneurysms.

OBJECTIVE: Chronic inflammation has earlier been detected in ruptured intracranial aneurysms. A previous study detected both dental bacterial DNA and bacterial-driven inflammation in ruptured intracranial aneurysm walls. The aim of this study was to compare the presence of oral and pharyngeal bacterial DNA in ruptured and unruptured intracranial aneurysms. The hypothesis was that oral bacterial DNA findings would be more common and the amount of bacterial DNA would be higher in ruptured aneurysm walls than in unruptured aneurysm walls. MATERIALS AND METHODS: A total of 70 ruptured (n = 42) and unruptured (n = 28) intracranial aneurysm specimens were obtained perioperatively in aneurysm clipping operations. Aneurysmal sac tissue was analysed using a real-time quantitative polymerase chain reaction to detect bacterial DNA from several oral species. Both histologically non-atherosclerotic healthy vessel wall obtained from cardiac by-pass operations (LITA) and arterial blood samples obtained from each aneurysm patient were used as control samples. RESULTS: Bacterial DNA was detected in 49/70 (70%) of the specimens. A total of 29/42 (69%) of the ruptured and 20/28 (71%) of the unruptured aneurysm samples contained bacterial DNA of oral origin. Both ruptured and unruptured aneurysm tissue samples contained significantly more bacterial DNA than the LITA control samples (p-values 0.003 and 0.001, respectively). There was no significant difference in the amount of bacterial DNA between the ruptured and unruptured samples. CONCLUSION: Dental bacterial DNA can be found using a quantitative polymerase chain reaction in both ruptured and unruptured aneurysm walls, suggesting that bacterial DNA plays a role in the pathogenesis of cerebral aneurysms in general, rather than only in ruptured aneurysms.

The connection between ruptured cerebral aneurysms and odontogenic bacteria.

BACKGROUND: Patients with ruptured saccular intracranial aneurysms have excess long-term mortality due to cerebrovascular and cardiovascular diseases compared with general population. Chronic inflammation is detected in ruptured intracranial aneurysms, abdominal aortic aneurysms and coronary artery plaques. Bacterial infections have been suggested to have a role in the aetiology of atherosclerosis. Bacteria have been detected both in abdominal and coronary arteries but their presence in intracranial aneurysms has not yet been properly studied. OBJECTIVE: The aim of this preliminary study was to assess the presence of oral and pharyngeal bacterial genome in ruptured intracranial aneurysms and to ascertain if dental infection is a previously unknown risk factor for subarachnoid haemorrhage. METHODS: A total of 36 ruptured aneurysm specimens were obtained perioperatively in aneurysm clipping operations (n=29) and by autopsy (n=7). Aneurysmal sac tissue was analysed by real time quantitative PCR with specific primers and probes to detect bacterial DNA from several oral species. Immunohistochemical staining for bacterial receptors (CD14 and toll-like receptor-2 (TLR-2)) was performed from four autopsy cases. RESULTS: Bacterial DNA was detected in 21/36 (58%) of specimens. A third of the positive samples contained DNA from both endodontic and periodontal bacteria. DNA from endodontic bacteria were detected in 20/36 (56%) and from periodontal bacteria in 17/36 (47%) of samples. Bacterial DNA of the Streptococcus mitis group was found to be most common. Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum and Treponema denticola were the three most common periodontal pathogens. The highly intensive staining of CD14 and TLR-2 in ruptured aneurysms was observed. CONCLUSIONS: This is the first report showing evidence that dental infection could be a part of pathophysiology in intracranial aneurysm disease.